Apparatuses of this kind are prior art. One area of application of such apparatuses is the conditioning of sealing gas. When handling corrosive process gases, for example, during pumping using turbo compressors, the known risk of sensitive parts of the pump, bearing points and/or sealing systems being attacked due to solid particles along with moisture present in the associated process gas exists. To counter this risk, sensitive parts, for example, the bearing points, must be protected by sealing gas in the form of a continuous flow of inert gas, with the inert gas flowing over the parts of the system to be protected. An appropriate inert gas may be dry nitrogen. During operation, the pressure of the sealing gas should be higher (for example, approximately 3 bar) than the process gas pressure, so that no process gas is able to pass into the atmosphere. In view of the usually high pressure of the process gas, frequently greater than 100 bar, the gas conditioning apparatus must be designed up to a high pressure level.